Safety mounting



Dem 1965 D. J. BRACC ZI ETAL 3,221,968

SAFETY MOUNTING Filed Jur xe 10, 1963 2 Sheets-Sheet 2 \lllllHlllllHHll ll United States Patent 3,221,968 SAFETY MOUNTING Delphio J. Bracci, Haverhill, and Jason M. Davidson,

Stoneharn, Mass., assignors to Western Electric Company, Incorporated, New York, N.Y., a corporation of New York Filed June 10, 1963, Ser. No. 286,685 5 Claims. (Cl. 22762) This invention relates to safety devices for apparatus having reciprocating driving members, and more particularly to mountings for the impact receiving member of such apparatus.

In apparatus such as a rivet setting machine where a power driven reciprocating member strikes an impact receiving member, there is normally a gap between the two members that may be of such a size that an operator may inadvertently place his hand therebetween and thereby incur an injury when the driven member moves downwardly. Reduciing the gap by shortening the length of the stroke of the reciprocating member tends to lower the elliciency of the machine by decreasing the force with which the reciprocating member strikes the impact receiving member.

Accordingly, it is an object of this invention to improve the safety of machines having reciprocating drivers without impairing the efficiency of the machines.

Another object of this invention is to provide a movable impact receiving member mounting to limit the distance between the driven reciprocating member and impact receiving member without affecting the active length of stroke of the former.

Other objects, features and a fuller understanding of the invention may be had by referring to the following description and claims taken in conjunction with the accompanying drawing, in which:

FIG. 1 is a partial, side elevation of a rivet setting machine incorporating a safety device embodying the principles of this invention; and

FIG. 2 is a partially cut-away front view of a mounting assembly for use with an impact receiving member on a riveting machine in accordance with the invention.

Referring now to the drawings, FIG. 1 depicts a partial side view of a rivet setting machine. As shown, this machine comprises an impact receiving member which includes an anvil unit 11, and a vertically reciprocating driver 12 disposed above the anvil unit. The driver 12 and anvil unit 11 cooperate to effect the setting of rivets 14 in parts to be fastened together.

As best seen in FIG. 2, the anvil unit 11 comprises a cylindrical member 30 having a pin 32 biased upwardly by a coil spring 31 and protruding a short distance beyond the top portion of the anvil unit. Although any type of anvil unit may be utilized in accordance with the invention, one with a spring-loaded pin is most advantageous for aligning the surfaces of two or more parts to be fastened together.

The driver 12 together with its mounting apparatus shown generally by reference numeral 13 may be reciprocated through the actuation of any suitable driving mechanism (not shown). A supply of rivets (not shown) is maintained in a feed chute 15. This chute is arranged to release a rivet during each cycle of operation into a position between a pair of yieldably mounted jaws 20. The jaws are arranged to hold successive rivets 14 in alignment with the driver 12. In operation, the holding jaws move downwardly with the driver until the rivet 14 contacts the anvil unit 11 whereupon the travel of the jaws ends. As the driver 12 continues forceably downwardly in engagement with the head of the rivet, the yieldably mounted jaws 20 are spread apart to reice lease the rivet previously held therebetween. The final impact of the driver upon the rivet in contact with the anvil unit 11 thereafter sets the rivet.

In accordance with an aspect of the invention, the anvil unit 11 is mounted on a spring-biased, vertically movable assembly 40. This assembly comprises a mounting body 47 fastened to a rigid support member 22, which, in turn, is supported by a bracket arm 24 affixed to the frame of the machine. Although the body 47 can be of various cross-sectional shapes, a hollow cylindrical tube-like form is preferred. A piston-like plunger 42, which is fastened to the anvil member 30 by means of the mutually engaging threaded sections 33, serves in part as a stop for the anvil coil spring 31.

Plunger 42 is vertically movable within an axial bore 37 of the mounting body 47 and biased upwardly by a coil spring 43. This spring is constructed to be much more resilient than spring 31 for reasons set forth in detail hereinafter. Movement of the piston-like plunger 42 upwardly beyond the top of body 47 is prevented by a retainer-collar stop 41. The length of the downward travel of the plunger 42 is controlled by an adjustable cup-shaped stop 44. An adjustment screw 46 threaded into the lower end of body 47 determines the vertical position of the downward stop 44. The adjustment screw 46 is locked in position by jam nut 45. The coil spring 43 thus presses against the downward stop 44 to exert a force on plunger 42, to which the anvil unit 11 is fastened, upward against the retaining collar 41.

In accordance with the invention, when the pin 32 of the anvil unit is first contacted by the rivet 14, no riveting action takes place. Rather, because of the resiliency of spring 43, the anvil unit 11 moves vertically downward with the plunger 42 until the latter contacts the adjustable stop 44. At that point, the anvil unit functions in accordance with its usual operation as if it had been fixedly located in the latter position. In the embodiment shown, the pin 32 then retracts and the rivet 14 is inserted and flared outwardly at its hollow end to fasten together the particular parts inserted in the machine.

It is thus readily seen that the gap between the anvil unit and the jaws 20 when in their unoperated state, can be limited to the distance determined by the location of the top of the anvil pin 32 in its protruding position. This distance is adjustable to of an inch in the illustrative embodiment, rather than the 2 inch minimum usually required to provide the necessary length of active stroke on conventional riveting machines. Accordingly, through the use of this invention, which considerably lessens the gap between the driver apparatus and anvil funit, injury to the hand of the operator by the driver is prevented without any actual alteration to or impairment of the operation of the machine.

It is to be understood that the above described embodiment is simply illustrative of the application of the principles of the invention. Numerous other arrangements may be readily devised by those skilled in the art which will embody the principles of this invention and fall within the spirit and scope thereof.

What is claimed is:

1. In a machine having a reciprocating driving member and an impact receiving means, apparatus for mounting said driving member and said impact receiving means in said machine so as to reduce the space therebetween without reducing the active stroke of the driving member comprising:

a body member having a channel therein which is in spaced relationship with said driving member,

a plunger mounted for rectilinear motion in said channel,

means attached to said body member for restricting the 3 rectilinear movement of said plunger between two predetermined limits in said channel, spring means mounted in said channel for biasing the plunger toward one of said predetermined limits,

a fixed hollow cylinder,

4 the plunger for normally holding the plunger in an upward position, and second spring means mounted above, and in contact with the plunger for normally urging the means connected to said body member for adjusting 5 movable anvil toward the driving means, said the quiescent position of said plunger and said impact second spring means having less resilience than receiving means relative to the driving member, the first spring means so that when the driving said impact receiving means including an anvil, and means strikes the anvil, first the plunger will a spring-loaded rod normally projecting upwardly retract within the cylinder, and then the anvil through the anvil a short distance beyond the upper will be retracted to eflfect the riveting operation. surface thereof, and 4. Apparatus for mounting a reciprocating driving the spring means biasing said plunger being more resilmember and impact receiving means of a riveting machine ient than said spring biasing the rod of said anvil so as to reduce the space therebetween without reducing such that upon the impact of the driving member with the active stroke of the driving member comprising: the upper end of said anvil rod, the spring-biased Mixed cylinder havingachannel therein, plunger is depressed downwardly until it abuts one a plunger having a cavity at one end thereof mounted of said predetermined limits for restricting the recfor rectilinear motion in Said channel, tilinear movement of said plunger whereupon the a rod mounted for rectilinear motion in said plunger rod of said anvil is depressed until said driving merny, Said d being in spaced relati nship With said her impacts the upper portion of said anvil which driving member, is rigidly su orted against aid lunger. first resilient means mounted in said cavity for biasing 2. In a machine having a reciprocating driver and an Said rod toward the driving member, associated anvil, apparatus for mounting the anvil so as P means mounted in the fiXed cylinder for limiting to reduce the required space between it and the reciprothe movement of the plunger away from said driving eating driver comprising: member, and

a cylindrical body having interior wall defining a onsecond resilient means mounted between the stop means centric cylindrical channel therein, and the plunger for biasing the plunger toward the means for rigidly connecting said cylindrical body to driving member, the second resilient means having the machine so that the concentric cylindrical changrfiater elasticity than the first resilient m lls S0 nel is in axial alignment with the path of the recipthat when the driving member strikes the rod, the rocating driver, plunger will retract in the channel until it abuts the a piston type support for said anvil mounted for recipp member, whereupon further movement of e rocal slidable contact along said walls of the cylindriving member Will depress the rod in Said cavity, drical channel, the riveting operation being effected at the end an upper stop including a collar screwed to the top of thereofthe cylindrical body for limiting the upward travel Mounting apparatus according to Claim 4 Whfireifll of said piston in the cylindrical channel, said stop means is threadedly mounted in said channel a lower stop including a slidable plug threadedly con- 50 as t be rectiiineariy afijustahie therein to thfirenected to a screw in the bottom portion of said cylinby li the Stroke of Said P r and drical body for limiting the downward travel of the a coma? threadedly mounted 011 said fixed cylinder piston in the cylindrical channel, and to l 1m1t the movement of the plunger toward the a coil spring located between the piston type support dnvmg member and the lower stop for pressing the piston type sup- References Cited by the Examiner port against the upper stop. 3. A riveting machine comprising: UNITED STATES PATENTS driving means, 660,705 10/1900 Kimman 87-50 an anvil mounted for movement with respect to the 1,444,909 2/1923 Gail 78-52 driving means, and 2,925,748 2/ 1960 Ross 7848 supporting means for the anvil including: 3,022,687 2/1962 Richards 7346 CHARLES W. LANHAM, Primary Examiner.

WILLIAM J. STEPHENSON, Examiner.

a plunger slidably mounted within the cylinder, first spring means mounted in the cylinder below 

1. IN A MACHINE HAVING A RECIPROCATING DRIVING MEMBER AND AN IMPACT RECEIVING MEANS, APPARATUS FOR MOUNTING SAID DRIVING MEMBER AND SAID IMPACT RECEIVING MEANS IN SAID MACHINE SO AS TO REDUCE THE SPACE THEREBETWEEN WITHOUT REDUCING THE ACTIVE STROKE OF THE DRIVING MEMBER COMPRISING: A BODY MEMBER HAVING A CHANNEL THEREIN WHICH IS IN SPACED RELATIONSHIP WITH SAID DRIVING MEMBER, A PLUNGER MOUNTED FOR RECTILINEAR MOTION IN SAID CHANNEL, MEANS ATTACHED TO SAID BODY MEMBER FOR RESTRICTING THE RECTILINEAR MOVEMENT OF SAID PLUNGER BETWEEN TWO PREDETERMINED LIMITS IN SAID CHANNEL, SPRING MEANS MOUNTED IN SAID CHANNEL FOR BIASING THE PLUNGER TOWARD ONE OF SAID PREDETERMINED LIMITS, MEANS CONNECTED TO SAID BODY MEMBER FOR ADJUSTING THE QUIESCENT POSITION OF SAID PLUNGER AND SAID IMPACT RECEIVING MEANS RELATIVE TO THE DRIVING MEMBER; SAID IMPACT RECEIVING MEANS INCLUDING AN ANVIL, AND A SPRING-LOADED ROD NORMALLY PROJECTING UPWARDLY THROUGH THE ANVIL A SHORT DISTANCE BEYOND THE UPPER SURFACE THEREOF, AND THE SPRING MEANS BIASING SAID PLUNGER BEING MORE RESILIENT THAN SAID SPRING BIASING THE ROD OF SAID ANVIL SUCH THAT UPON THE IMPACT OF THE DRIVING MEMBER WITH THE UPPER END OF SAID ANVIL ROD, THE SPRING-BIASED PLUNGER IS DEPRESSED DOWNWARDLY UNTIL IT ABUTS ONE OF SAID PREDETERMINED LIMITS FOR RESTRICTING THE RECTILINEAR MOVEMENT OF SAID PLUNGER WHEREUPON THE ROD OF SAID ANVIL IS DEPRESSED UNTIL SAID DRIVING MEMBER IMPACTS THE UPPER PORTION OF SAID ANVIL WHICH IS RIGIDLY SUPPORTED AGAINST SAID PLUNGER. 